The Power of the F5 key!!
At the first chord in the bar where you want to tempo to change, hit F5 and do your thing in there, either by % or by bpm.
Remember to rest the tempo back to the original at the bar where the Chorus starts by F5'ing that bar.
If you wanted (say) the last 4 bars to slow down, each one slower than the previous one, you would have to make the changes bar by bar as AFAIK there is no ritardando feature in B. I have done it a few times after Mac led me through it once upon a time and it works but is laborious.
Always reset the fist bar of Chorus back where you want it though.

HTH
Ian

Old Guys Rule.The older I get,the better I was!
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